Abstract: A half-rack electronics cabinet coupled to a wall mount by two doubly-nested four bar mechanisms that are operable to articulate the cabinet by ninety degrees to bring the back planes of any installed electronic modules to the top for easy access. The function of admitting outside signal and power cables is apportioned to the wall mount. The unit is compact, as the wall mount is no wider than the cabinet. For a half-rack cabinet of sufficient height, crossbars are provided that enable vertical mounting of full-rack electronic modules in the half-rack cabinet along with, preferably, at least one half-rack module.

Abstract: Crossbars span the width between two opposed vertical attachment bars in a half-width electronics rack or cabinet of accommodating height to enable vertical mounting of full-width electronics module in the half-width electronics rack or cabinet. The crossbars are used in opposed spaced-apart pairs with the full-width electronics module mounted vertically between the crossbars. Each crossbar includes a flat elongated main bar having five sets of three holes in a linear array, with the holes sized and spaced apart in accordance with industry standards for electronics racks. An attachment flange with a fastener opening extends from each end of the main bar and is delineated from the main bar by a notch. Between the notches, the same edge extends in a right-angle bend which further extends into a flange. Crossbars are provided in pairs, with or without packaging, racks, cabinets, and electronics modules.

Abstract: A pole-mountable electronic chassis for mounting on an equipment support pole, including at least one enclosure for electronic circuitry and at least one passage completely through the enclosure sized, shaped, and arranged for receiving the pole. A passage web surrounds the passage and may optionally provide thermal conductivity or circuit support functions. A coupling is provided for fixing the enclosure in place. The coupling may be a low-profile coupling. The enclosure may be sized and shaped to also fit in industry-standard electronics racks.

Abstract: A pole-mountable electronic chassis for mounting on an equipment support pole, including at least one enclosure for electronic circuitry and at least one passage completely through the enclosure sized, shaped, and arranged for receiving the pole. A passage web surrounds the passage and may optionally provide thermal conductivity or circuit support functions. A coupling is provided for fixing the enclosure in place. The coupling may be a low-profile coupling. The enclosure may be sized and shaped to also fit in industry-standard electronics racks.

Abstract: A modular horn loudspeaker principally intended for use on emergency vehicles consists of three coaxially aligned cup-shaped parts, a sound chamber, a cover fitted to the sound chamber and a housing. The first embodiment of the modular, compact horn loudspeaker is implemented with a single siren driver and includes a dome-shaped driver diaphragm integrally formed onto an interior surface of the sound chamber. The sound chamber is an acoustical boundary defining member having curved propagation paths or horn throat channels formed in relief on a cup-shaped exterior surface. The sound chamber is coaxially aligned with and received in a tightly fitted cup-shaped cover member to define a plurality of curved horn throats of expanding rectangular cross sectional dimension directing the sound waves rearwardly around the diaphragm periphery and toward a housing rear wall.

Abstract: A plenum mounted, flat metal panel diaphragm masking loudspeaker includes a flat, stamped sheet metal frame which has a deployed state and an undeployed, flat state well suited to storage or shipping. A large, movable tab at the bottom of the frame is weakened by a series of small apertures and forms a hinge or fold line. Electrical accessories including a transformer, a rotary switch for selecting transformer taps and signal connections are included in an enclosed box mounted on the foldable tab. The flat panel masking loudspeaker is shipped flat in the undeployed state and then the large tab is deployed by being folded outwardly before installing the flat panel masking loudspeaker in a ceiling plenum. During installation, the tab is folded along the hinge or fold line out to approximately 90.degree.

Abstract: A folding microphone stand has a stand tube which is pivotally supported in heavy cast base. Locking means are provided for securing the stand tube in an erect or a stored position.

Abstract: A miniaturized cone driven reentrant loudspeaker is provided. A cone spea is positioned within a housing. The housing includes a front wall for radiating sound and a side wall. The cone speaker is directed towards a reflector back plate having a generally spherical surface which protrudes into the cone speaker for directing sound waves towards sidewalls of the housing to define a miniaturized cone driven reentrant loudspeaker.

Abstract: A microphone stand assembly incorporating an adjustable pivot for allowing a microphone support column to be securely oriented in at least two positions is provided. Interchangeable single and dual pivots accommodate either one or two microphone support columns. The dual pivot permits a performer to utilize a single microphone stand with two microphones at different heights for simultaneous voice and musical instrument amplification.